update

Author: deleiguo

source/java/interview/delei-interview-java-core/src/main/java/cn/delei/java/JVMTest.java

@@ -1,12 +1,16 @@
 package cn.delei.java;
 
+import java.util.ArrayList;
+import java.util.List;
 import java.util.stream.IntStream;
 
 public class JVMTest {
 
-    public static void main(String[] args) {
+    public static void main(String[] args) throws Exception {
         //CMSTest();
-        G1Test();
+        //G1Test();
+        //stackOverFlow();
+        //outOfMemory();
     }
 
     static void CMSTest() {
@@ -19,6 +23,20 @@ static void G1Test() {
         test();
     }
 
+    static void outOfMemory() {
+        // -Xms1M -Xmx10M
+        List<JVMTest> data = new ArrayList<>();
+        //无限创建对象，在堆中
+        while (true) {
+            data.add(new JVMTest());
+        }
+    }
+
+    static void stackOverflow() {
+        // -Xms1M -Xmx10M -Xss1M
+        stackOverflow();
+    }
+
     static void test() {
         int size = 1024 * 1024;
         IntStream.range(0, 11).forEach(e -> {

source/java/interview/delei-interview-java-core/src/main/java/cn/delei/java/util/HashMapDemo.java

@@ -1,6 +1,7 @@
 package cn.delei.java.util;
 
 import cn.delei.util.HashCodeUtil;
+import cn.delei.util.PrintUtil;
 
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
@@ -17,8 +18,8 @@ public class HashMapDemo {
     public static HashMap<String, String> hashMap;
 
     public static void main(String[] args) {
-        //opera();
-        calcInitCapacity();
+        opera();
+        // calcInitCapacity();
     }
 
     /**
@@ -28,6 +29,7 @@ static void opera() {
         try {
             int capacity = 7;
             hashMap = new HashMap();
+            PrintUtil.printDivider("反射获取内部变量值");
             // 使用反射
             Class mapClass = hashMap.getClass();
             Field tableField = mapClass.getDeclaredField("table");
@@ -48,7 +50,9 @@ static void opera() {
                         , thresholdField.get(hashMap), hashMap.size());
             }
             // put 相同 hashcode 的 key
-            List<String> hashSting = HashCodeUtil.generateN(11);
+            PrintUtil.printDivider("put 相同 hashcode 的 key");
+            hashMap = new HashMap();
+            List<String> hashSting = HashCodeUtil.generateN(5);
             int h = hashSting.get(0).hashCode();
             int hash = h ^ (h >>> 16);
             System.out.println("Hashcode:" + hash);